Parasites cause significant economic losses to agriculture worldwide due to poor productivity, limited growth rates and death. According to some estimates, the financial damage caused by parasites to the livestock industry is in the order of tens of billions of dollars per annum. Decreased productivity influences not only the livestock industry but also substantially affects global food production. Moreover, in spite of the anthelmintic drugs discovered and marketed in the last decades, problems of parasitic worms persist and multi-drug resistance to most classes of anthelmintics is widespread. The development of new classes of anthelmintics is a major priority. Any anthelmintic developed for parasites of livestock would also have application to parasites of humans and other animals, including companion animals, such as dogs, cats and equids. One sixth of the human population in earth is affected chronically by at least one parasitic helminth, and the socioeconomic burden (in DALYs) is greater than that of cancer and diabetes. Some helminths, such as Schistosoma haematobium, Opisthorchis viverrini and Clonorchis sinensis induce malignant cancers in humans.
Recently, a new class of synthetic anthelmintics referred to as Amino-Acetonitrile Derivatives (AADs, see WO2005/044784A1), has been commercially developed under the trade name Zolvix® for the treatment of infected sheep.
Monepantel (AAD 1566)

The precise mode of action of monepantel is not yet elucidated, although an interaction of AADs with a specific acetylcholine receptor (nAChR) subunit has been proposed. This target is only present in nematodes but not in mammals, making it relevant for the development of a new class of anthelmintic drugs. Of high importance, a mutant of Haemonchus contortus with a reduced sensitivity to monepantel was recently identified using a novel in vitro selection procedure (L. Rufener, R. Baur, R. Kaminsky, P. Maeser and E. Sigel, Mol. Pharmacol., 2010, 78, 895-902), indicating that resistance will develop in gastrointestinal nematodes of livestock. This observation has been noticed for all current anthelmintics on the market. In light of the above referenced state of the art, the objective of the present invention is to provide novel compounds to control parasites of human beings and livestock.
This objective is attained by the subject-matter of the independent claims.